A monolithic radio frequency/microwave power detector, implemented for example as a bipolar or complementary metal-oxide semiconductor device, would offer a number of advantages for embedded testing of a radio frequency (RF) integrated circuit (IC). The advantages of such a detector include its simplicity, wide bandwidth, low power consumption, small chip size, and temperature stability.
Notwithstanding these advantages, a persistent problem posed by the use of such a detector is its wide crossover region. As with any bipolar-based peak detector, the crossover region of the detector is its region of operation, which lies between a region in which the detector exhibits high-voltage linear behavior and another region in which the detector exhibits low-voltage square-law behavior. It is difficult to predict the strength of an input signal accurately when a device operates in the crossover region; preferably, signal detection occurs with the device operating in the region in which it exhibits high-voltage linear behavior.
Accordingly, in the context of providing an on-chip detector for small-signal power detection, there is a need for a detector that effectively and efficiently amplifies the signal prior to its detection.